When Maryland Attorney General J. Joseph Curran Jr. recruited 500 senior volunteers last fall, assigning them the unenviable task of saving a month's worth of suspect sweepstakes solicitations and dream vacation offers, he expected a mountain of mail. But 10,000 letters? In only 30 days?

"It's such a deluge," Curran marveled this week as those letters began to be sorted, bin by bin, for investigation and possible prosecution. "So much of it is "Congratulations!' or "You've won!' It looks so very attractive."

Looks are dangerously deceiving in the world of scam artists -- a $40-billion-a-year world of "boiler rooms" and "mooch" lists in which the elderly often play the role of sucker. During the last two years, law enforcement and government at both the national and state levels have made stopping these fraudulent telemarketing and mail schemes an increasingly high priority. They think they're beginning to succeed.

In Operation Senior Sentinel, the first nationwide attempt to shut down telemarketers through criminal prosecutions, the U.S. Justice Department has charged about 1,000 people since the first arrests in December 1995.

In Project Mailbox, launched last fall, federal officials have reviewed more than 5,000 solicitations, and a strike force that includes state attorneys general, postal inspectors and the American Association of Retired Persons is turning to enforcement as well as education strategies.

Maryland's Senior Sting, as it is dubbed, is one effort, and Curran, now 66 himself, considers it "poetic justice" that people like Jack Waters, of Bowie, Md., may help flush out the crooks. The retired Army employee got recruited for the project through his AARP chapter, and he was more than happy to participate.

"It takes the person who is targeted to ... cut this down or cut it out," said Waters, 78.

On any given week, nearly half a dozen unwanted letters show up in his mailbox, to say nothing of the smooth-talking callers who always seem to interrupt his dinner hour with his wife.

"Like everybody else, we're bothered a lot," Waters complained. He's especially annoyed by the West Coast sweepstakes outfit that won't leave him alone. "They send all sorts of colorful envelopes and colorful stories," he said. "You know, `Take advantage of this, Mr. or Mrs. So-and-So. You are high on the list.'"

The attorney general's office will review the mail gathered for the next several months. By summer, Curran, a Democrat, expects to start announcing companies that he will pursue with charges or cease-and-desist orders. He also wants to use the solicitations in "education alerts" that will be presented in senior centers around the state.

Curran is not unfamiliar with direct-mail sales pitches that cross the line. In 1995, he secured a $2.6 million settlement from Outdoor World Corp., which Curran contended had lured thousands of Maryland residents to rural campgrounds by falsely promising valuable prizes. This year, he's also going after telephone fraud with legislation to allow Maryland consumers, under the auspices of law enforcement, to secretly record telemarketers' calls.

Senior Sting reflects his particular concern for older men and women such as a retired neighbor, an active, educated person, who came to him one Sunday and confessed he'd lost thousands of dollars through a scheme offering lucrative business opportunities. "It made me think that not everybody (bilked) is sitting at home lonely and easily fooled," Curran said.

AARP surveys have shown as much. "Contrary to anecdotal evidence, most victims of telemarketing fraud are not lonely, isolated or confused," the organization concluded after a 1995 study, part of a continuing initiative to educate seniors about telemarketing fraud.

According to AARP, people over 50 are a primary target of illegal sweepstakes, bogus charities, investment scams and deceptive lotteries, and they're often disproportionately victimized.

"It angers me," said Rusch, who has heard some egregious pitches. Many, he said, rely on psychological manipulation or browbeating. The public got a sense of that when the initial arrests were made in Operation Senior Sentinel and the FBI released tapes of solicitation calls that senior recruits recorded.

The vast majority of those charged in the crackdown, which continues, have pleaded guilty. "It's in the high hundreds," Rusch said.

In Las Vegas the number of boiler rooms -- equipped with little more than phones and desks --has been cut from dozens to fewer than 10, and in cities such as Chattanooga, Tenn., "there is no longer telemarketing of the fraudulent variety," he declared.